Beef jerky is a dried meat snack which is rich in protein but of low calorific value. This ready-to- eat meat snack is in high demand among hikers, bikers and travelers due to its compact nature and nutritional value. The current processing methods such as smoke house and home dehydrators take 6-10 h. Increasing market for this shelf-stable meat product increases the need for alternate efficient processing method. Also, this meat snack market depends on its textural characteristics which denote the consumer acceptability. In this research, three different methods of drying beef jerky were examined. Influences of pH and salt on different characteristics of beef jerky were investigated using combined microwave-convection drying. Also, the effects of relative humidity and airflow rates in forced air thin layer drying on jerky processing were studied. Samples of beef jerky dried using a combined microwave-convection drier and thin layer drying unit were compared with samples dried in a smoke house. The results obtained showed that pH and salt content had a significant influence on drying, physical and textural characteristics of jerky. It was found that samples with low pH (5.15) and high salt content (3.28% (w/w)) dried faster than samples with high pH and low salt content due to their high drying rates. These samples had shown high shrinkage and weight loss compared to samples with pH 5.65 and 1.28% (w/w) salt content. Analysis of the textural characteristics such as tensile force, puncture force and texture profile showed that the samples with high pH and low salt content were comparably softer than the rest of the samples. Results of the effect of relative humidity and airflow rate in forced air thin layer drying on jerky processing showed that relative humidity and airflow rate influenced the drying, physical, chemical and textural characteristics of beef jerky. Combination of low relative humidity and high airflow rate showed desirable drying characteristics. However, samples dried at this combination showed high shrinkage and weight loss. The hardness of the beef jerky increased with increase in airflow rate and reduction in relative humidity. A comparison of the drying methods revealed that different drying methods produced different desirable properties. Combined microwave-convection drying was found to be efficient and very rapid (8.25 min). The low shrinkage and weight losses along with high drying rate obtained using this method would pave a way to fast and efficient processing. The color and textural characteristics were different from those of samples dried in a smoke house. Surprisingly, combined microwave-convection drying method produced softer beef jerky than thin layer and smokehouse methods. However, the commercially available jerky is tougher than the one dried using combined microwave-convection drying. The samples dried in a thin layer drier had comparable color and textural characteristics with samples dried in a smoke-house. Also, forced-air thin layer drying method reduced drying time of beef jerky from 7 to 3 h. The forced air thin layer drier has the potential to produce beef jerky with similar color and textural characteristics to commercially available smoke house dried samples.

Beef jerky is a dried meat snack which is rich in protein but of low calorific value. This ready-to- eat meat snack is in high demand among hikers, bikers and travelers due to its compact nature and nutritional value. The current processing methods such as smoke house and home dehydrators take 6-10 h. Increasing market for this shelf-stable meat product increases the need for alternate efficient processing method. Also, this meat snack market depends on its textural characteristics which denote the consumer acceptability. In this research, three different methods of drying beef jerky were examined. Influences of pH and salt on different characteristics of beef jerky were investigated using combined microwave-convection drying. Also, the effects of relative humidity and airflow rates in forced air thin layer drying on jerky processing were studied. Samples of beef jerky dried using a combined microwave-convection drier and thin layer drying unit were compared with samples dried in a smoke house. The results obtained showed that pH and salt content had a significant influence on drying, physical and textural characteristics of jerky. It was found that samples with low pH (5.15) and high salt content (3.28% (w/w)) dried faster than samples with high pH and low salt content due to their high drying rates. These samples had shown high shrinkage and weight loss compared to samples with pH 5.65 and 1.28% (w/w) salt content. Analysis of the textural characteristics such as tensile force, puncture force and texture profile showed that the samples with high pH and low salt content were comparably softer than the rest of the samples. Results of the effect of relative humidity and airflow rate in forced air thin layer drying on jerky processing showed that relative humidity and airflow rate influenced the drying, physical, chemical and textural characteristics of beef jerky. Combination of low relative humidity and high airflow rate showed desirable drying characteristics. However, samples dried at this combination showed high shrinkage and weight loss. The hardness of the beef jerky increased with increase in airflow rate and reduction in relative humidity. A comparison of the drying methods revealed that different drying methods produced different desirable properties. Combined microwave-convection drying was found to be efficient and very rapid (8.25 min). The low shrinkage and weight losses along with high drying rate obtained using this method would pave a way to fast and efficient processing. The color and textural characteristics were different from those of samples dried in a smoke house. Surprisingly, combined microwave-convection drying method produced softer beef jerky than thin layer and smokehouse methods. However, the commercially available jerky is tougher than the one dried using combined microwave-convection drying. The samples dried in a thin layer drier had comparable color and textural characteristics with samples dried in a smoke-house. Also, forced-air thin layer drying method reduced drying time of beef jerky from 7 to 3 h. The forced air thin layer drier has the potential to produce beef jerky with similar color and textural characteristics to commercially available smoke house dried samples.

The present research seeks to study the decrease in diffusivity rate as relative humidity (RH) decreases and modeling drying shrinkage of hardened cement paste as a poroviscoelastic respose. Thin cement paste strips of 0.4 and 0.5 w/c at age 3 and 7 days were measured for mass loss and shrinkage at small RH steps in an environmental chamber at constant temperature. Non-linear drying diffusion rate of hardened cement was modeled with the use of Fick's second law of diffusion by assuming linearity of diffusion rate over short drops of ambient relative humidity. Techniques to determine drying isotherms prior to full equilibration of mass loss, as well as converting mass loss into concentration of water vapor were developed. Using the measured water vapor diffusivity, drying shrinkage strain was modeled by the theory of poroviscoelasticity. This approach was validated by determining viscoelastic properties from uniaxial creep tests considering the effect of aging by the solidification theory. A change in drying diffusion rate at different RH was observed in the 0.4 and 0.5 w/c pastes at different ages. Drying diffusion rate decreases as RH drops. This can be attributed to a change in diffusion mechanisms in the porous media at smaller pore radius. Shrinkage modeling with an average diffusion coefficient and with determined viscoelastic parameters from creep tests agreed well compared to the shrinkage data from experiments, indicating that drying shrinkage of cement paste may be considered as a poroviscoelastic reponse.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1956. / Includes bibliographical references (p. 95-97).

This study is aimed to compare the fluidized bed and microwave drying with microwave assisted fluidized bed drying. For this purpose, macaroni beads (2.4&plusmn / 0.08 mm diameter) were dried from about 20% to 12% moisture content in a fluidized bed of 7.6 cm diameter, in a domestic microwave oven with a power of 609 W and in the fluidized bed placed in the microwave oven conditions. In the experiments with the fluidized bed three air temperatures / 50, 60 and 70&deg / C at an air velocity of 2.3 m/s and in those with the microwave oven two power levels / 50% and 100% were used. The drying curves indicated that the drying rate increased with the air temperature and microwave power in each drying method. Microwave assisted fluidized bed drying reduced the drying time by about 50% and 11% on the average compared with the fluidized bed and microwave drying, respectively. Therefore, it was concluded that the drying time was reduced more by the effect of microwave energy than the fluidization. The effective diffusivities in the fluidized bed and microwave assisted fluidized bed drying were found to be in the order of 4.125x10-11 and 8.772x10-11 m2/s on the average, respectively. The effective diffusivities for the fluidized bed drying were fitted to an Arrhenius type of equation and the magnitude of the activation energy was found to be in the order of 12595 kJ/kg mol.

The main objective of this work is to investigate whether the time required to dry red peppers in the diffusion controlled period can be reduced. For this purpose, the possibility of microwave drying in this period was studied. As comparison parameters the drying rates and color of the products were selected. The conventional drying was conducted under constant external drying conditions with air at 60 0C and 3.5 % RH and 1.0 m/s velocity in a batch dryer. For the microwave drying a domestic microwave oven with three power levels, 286, 397 and 560 W was used. Pre-experiments were done to obtain an insight on the possibility of moisture distribution within the structure of the red peppers and electrical field distribution inside the oven cavity. The non-uniformity due to the latter effect was tried to be overcome by designing and installing a six blade impeller into the bed having the symmetrical pair of blades fixed at three levels. Samples for the microwave drying experiments were prepared by drying the peppers from approximately 90% of moisture to 20% in 7 hours in the conventional dryer at 600C and then cutting them into pieces about 1x1 cm. Thus prepared samples were dried further in the microwave oven to 14% moisture content without and with the agitator. To compare the results, the effective diffusivity coefficients were calculated for all of the methods and parameters to enable the aimed comparison. These indicated that by using microwave drying, the drying time can be reduced by about 120 times. Further, by mixing the uniformity of drying and the drying rate could be improved. Considering color of the product, there was no significant difference with respect to the fresh samples after all operations.

A liberação local de fármacos na cavidade oral apresenta muitas aplicações, incluindo o controle da dor pós-cirúrgica, tratamento de doenças periodontais e anestesia local. Micropartículas carregadas com anti-inflamatórios não-esteroidais (AINEs) produzidas para a liberação sustentada é útil em Odontologia, uma vez que mantém o fármaco em níveis terapêuticos, promove o controle da dor e maior adesão do paciente ao tratamento.Uma vez que o sistema é biodegradável, o paciente não precisa ir ao consultório do dentista para removê-lo. Spray drying, é um dos vários métodos de microencapsulação, é rápido, de fácil operação, ampliação de escala e apresenta condições moderadas de operação. Assim, o objetivo deste trabalho é determinar as especificações do processo de spray-drying na obtenção de micropartículas biodegradáveis para a liberação sustentada de fármacos com aplicação odontológica. Quitosana foi utilizada como polímero de revestimento, uma vez que é biodegradável, biocompatível e mucoadesivo. Cetoprofeno foi utilizado como AINE modelo.Testes de qualificação de operação do spray-dryer foram conduzidos em conformidades com os requisitos da ANVISA e FDA. O método de análise de teor de cetoprofeno também foi validado, apresentando precisão, exatidão, linearidade e especificidade adequados ao seu propósito. Com relação ao processo de microencapsulação, a melhor condição operacional no spray-dryer apresenta 100 ºC de temperatura de entrada, 5,7 g/min de vazão da bomba peristáltica, 49,2 m3/h de vazão do ar de secagem, 1 mm de diâmetro do bico atomizador e 1,3 de pressão do ar comprimido. As micropartículas obtidas apresentam boa esfericidade e uma superfície lisa. A distribuição granulométrica é estreita, variando de 2,11 a 3,27m. Os estudos de liberação in vitro mostram um comportamento linear de dissolução do cetoprofeno encapsulado nas micropartículas, sugerindo que a cinética de liberação do fármaco é governada pela dissolução do fármaco e difusão através da matriz polimérica. Quitosana apresentou influência sobre a liberação do cetoprofeno, uma vez que foi encontrado um T50 de 36,0 h para o fármaco microencapsulado, ao passo que para o fármaco livre o T50 é de apenas 7,84 h. / Local release of drugs at oral cavity tissues shows several uses, including postsurgery pain control, periodontal disease treatment and local anesthesia. NSAID loaded-biodegradable microparticles made for a sustained drug release is useful in Dentistry since they keep the drug therapeutic level sustained, promote pain control and patient compliance. Since the system is biodegradable, the patient do not need to go to the dentistry office to remove it. Spray-drying (SD) , one of the several microencapsulation methods, is fast, has easy operation and scale-up and shows mint operating conditions. Thus the aim of this work is to design the spraydrying specifications of manufacturing dental drug loaded-biodegradable microparticles for sustained release purposes. Chitosan was used as the microencapsulation polymer due to its biodegradability, biocompatibility and mucoadhesiveness. Ketoprofen was used as the model NSAID. Operation qualification tests were performed with the spray-dryer as required by ANVISA and FDA. The analytical method for ketoprofen assay was also validated, showing accuracy, precision, linearity and specificity suitable for its purpose. Concerning microencapsulation process, the best SD operating conditions was 100 º C (inlet), 5,73 g/min (pump flow rate), 49,19 m3/h (air flow rate), 1 mm (nozzle), 1,3 (compressed air). The microparticles delivered show good sphericity and a smooth surface. The size distribution is narrow, ranging from 2,11 to 3,27 m. In vitro release studies show a linear dissolution behavior of cetoprofen-loaded microparticules suggesting the kinetic of drug release is driven by drug dissolution and diffusion through polymer matrix. Chitosan has an influence over the cetoprofen release since a T50 of 36,0 h was found to microparticles while the cetoprofen only has a T50 of 7,84 h.

Orientador: Elias Basile Tambourgi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-18T00:23:05Z (GMT). No. of bitstreams: 1 Oi_RicardoKenji_D.pdf: 1297079 bytes, checksum: b8560146dcb2fcbcd466b168329ba846 (MD5) Previous issue date: 2011 / Resumo: A biomassa de banana verde é um componente que pode ser aplicado industrialmente em uma grande variedade de alimentos por não interferir nos atributos sensoriais de outros ingredientes e apresentar propriedades funcionais, sobretudo pela presença do amido resistente. O campo de aplicação pode ser ampliado, inclusive para a exportação, se produzido na forma de pó. O presente trabalho apresenta um estudo de viabilidade de secagem da biomassa de banana verde em uma unidade não comercial (experimental) de spray dryer com atomizador rotativo. As variáveis selecionadas no procedimento experimental foram: o tipo do atomizador (tipo A, de orifícios de forma retangular com semicírculos nas extremidades e área total de 162,88 mm2 e tipo B de orifícios de forma circular e área total de 254,47 mm2); a concentração da suspensão; a rotação do atomizador; a temperatura da alimentação e a vazão da alimentação. A temperatura da câmara foi fixada em 140ºC com o ar a 0,013 kg/s. Estabeleceu-se como respostas a massa e a umidade relativa do produto. Essas variáveis tiveram dois níveis de variação, o que correspondeu à realização de 32 ensaios. Dentre as variáveis utilizadas nos ensaios, a concentração da suspensão foi a variável mais significativa para as repostas massa e umidade relativa, as demais apresentaram efeitos reduzidos. O ensaio número 13 apresentou as melhores condições das respostas (9,17% e 12,656 g), sendo obtido com o atomizador tipo B; concentração de 50%, rotação de 27.000 rpm, vazão da alimentação de 40 mL/min e temperatura da alimentação de 30 ºC. Para esta amostra foi realizada uma análise microscópica, em que o tamanho dos grânulos não ultrapassou 500 ?m, portanto, pode ser empregado em diversas preparações alimentícias. A partir do ensaio 13, calculou-se o diâmetro da câmara de secagem para uma produção de 25 kg/h, o que resultou em 5,14 m. Neste estudo ficou comprovada a viabilidade da secagem da biomassa de banana verde em spray dryer com atomizador rotativo / Abstract: The green banana biomass is a component that can be industrially applied to a wide variety of foods because do not interfere in the sensory attributes of other ingredients present and has functional properties, especially the presence of resistant starch. This use can be expanded, including for export, if this product be produced in powder form. This research presents a feasibility study of drying green banana biomass in a non-commercial unit (experimental) of spray dryer with rotary atomizer. The variables selected in the experimental procedure were: the type of atomizer (type A, hole in a rectangular shape with semicircles at the ends and the total area of 162.88 mm2 and type B, hole in a circular shape and a total area of 254.47 mm2); the suspension concentration; the atomizer rotation; the biomass temperature and the biomass flow. The chamber temperature was set at 140ºC with air at 0.013 kg/s. It was defined as response the mass and the relative humidity of the product. These variables had two levels of variation, which corresponded to the completion of 32 trials. Among the variables used in the tests, the suspension concentration was the most significant to responses of mass and humidity, the others showed low effects. The test number 13 presented the best conditions of responses (9.17% and 12.656 g), was obtained with the atomizer type B, 50% concentration, atomizer rotation of 27,000 rpm, biomass flow rate of 40 mL/min and biomass temperature of 30°C. For this sample was realized a microscopic analysis, the granules size do not exceeded 500 ?m, therefore can be used in various food preparations. From the 13 test, the diameter calculation of the drying chamber for a production of 25 kg / h resulted in 5.14 m. In this study it was proved the feasibility of drying the green banana biomass in a spray dryer with rotary atomizer / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

M.Tech. (Mechanical Engineering) / Please refer to full text to view abstract

The process of spray drying consists of dispersing a liquid to be dried into a hot desiccating medium. This operation is carried out in a chamber where the process is completed, and from which the dried product is removed. Due to the tremendous surface area of the dispersed particles and intimate contact of the particles with the drying medium, the drying time is reduced to a minimum These facts along with the fact that the particle is not heated above the wet bulb temperature of the drying medium, make the process particularly adaptable to drying heat sensitive materials. Although, the theory for spray drying is similar to that for other drying processes, it is complicated by the aerodynamics of small particles suspended in a turbulent medium. Neither quantitative data nor mathematical relationships are available in the literature which would enable spray drying equipment to be designed on the basis of calculated drying rates. A study of the numerous variables encountered in drying materials by this process should be very helpful for future design work. The purpose of this investigation was to determine how variable factors such as condition of feed, atomizing variables, and chamber conditions affected the moisture content, bulk density, and particle size of a spray dried material. These variables were studied in a unit constructed at the Virginia Polytechnic Institute according to plans based on available information, and cut and try experimental work. Sodium sulphate was dried in this unit with the concentration, temperature and pressure of the feed; temperature and pressure of the atomizing air; and temperature of the drying air varied from an arbitrary set of operating conditions. The product from these runs was analyzed for its moisture content, bulk density, and particle size. The results of these analysis indicated that the concentration of the feed was the most significant variable tested. A variation of 25 to 200 per cent saturation at room temperature reduced the specific surface from 24.04 to 20.00, reduced the bulk density from 2.5 to 2.2 grams per cc and also reduced the moisture content from 1.16 to 0.55 per cent. Increasing the temperature of the atomizing air from 75 to 200° F and temperature of the atomizing air from 95 to 200° F was found to have almost no effect on the variables tested. Varying the atomizing air pressure from 8 to 26 pounds per sq. in. reduced the moisture content from 0.58 to 0.47 per cent and increased the bulk density of the product from 2.2 to 2.4 grams per cc without any definite trend in specific surface. The bulk density was decreased from 2.5 to 2.5 grams per cc when the temperature of the chamber air was increased from 150 to 236° F. Variation in the specific surface factor indicated that the particle size increased and the moisture content remained constant for this run. / Master of Science